Adhesive packaging system

ABSTRACT

A two part adhesive packaging system is provided. The packaging system includes two containers for holding a two-part adhesive. The packaging system further includes a connector having two ports for communicating with the containers. A membrane is adhered overtop the ports to prevent the two-part adhesive from draining from the containers. The membrane is configured to break upon application of a sufficient force thereon, such as by pumping or pushing the two-part adhesive from the containers.

CROSS-REFERENCE

This application claims the benefit of U.S. Provisional Application No. 61/539,271, filed Sep. 26, 2011. The entire contents of the above application are incorporated herein by reference.

FIELD

The present invention relates to an adhesive packaging system, and more particularly to an adhesive packaging system used in an applicator for dispensing an two-part adhesive on a roofing substrate.

BACKGROUND

In many roofing applications, for example in large, flat commercial roof decks, a roofing membrane is used to seal and protect the roof deck from environmental weather conditions. The roofing membrane may be made of various materials, such as polymeric materials including EPDM (ethylene propylene diene M-rubber) or TPO (thermoplastic polyolefin). The roofing membrane is adhered overtop insulation boards or cover boards. The insulation boards are typically secured to the roofing substrate or roof deck via an adhesive composition. A conventional adhesive composition used to adhere the insulation boards to the roof deck, or used to adhere roofing membranes to rigid insulation boards, cover boards, or directly to the roof deck, includes polyurethane. The polyurethane adhesives are oftentimes applied directly onto the roof deck via an applicator system and the insulation boards are then laid onto the roof deck surface. Conventional polyurethane adhesives oftentimes include two separate parts that are mixed by an applicator just prior to being applied onto the surface of the roof deck. The two parts include an isocyanate blend and a simple polyol blend. Upon mixing, the isocyanate blend reacts or crosslinks with the simple polyol blend to form the polyurethane adhesive.

These conventional two-part polyurethane adhesives must be packaged into separate containers to prevent mixing of the adhesive parts prior to application. In certain configurations, the adhesive parts are packaged into a single system having divided, separately sealed sides for storing the adhesive parts. Upon removal of a port cap, the adhesive sides communicate with an attached nozzle. However, if the nozzle is attached and then stored, it is possible for the adhesive parts to drain into the nozzle prior to application, crosslink, and plug the nozzle or the package with cured polyurethane. Therefore, there is a need in the art to provide an adhesive packaging system that prevents unwanted mixing of the adhesive parts prior to application on a substrate, but after the attachment of the mixing nozzle.

SUMMARY

A two part adhesive packaging system is provided. The packaging system includes two containers for holding a two-part adhesive. The packaging system further includes a connector having two ports for communicating with the containers. A membrane is adhered overtop the ports to prevent the two-part adhesive from draining from the containers. The membrane is configured to break upon application of a sufficient force thereon, such as by pumping or pushing the two-part adhesive from the containers.

DRAWING DESCRIPTION

FIG. 1 is a side view of a packaging system according to the principles of the present invention;

FIG. 2 is a top view of the packaging system shown in FIG. 1 with a cap removed;

FIG. 3 is a cross-section view of the packaging system viewed in the direction of arrow 3-3 shown in FIG. 2;

FIG. 4 is a perspective view of the packaging system with a mixing nozzle shown in an exemplary applicator device;

FIG. 5 is a top view of an alternate packaging system according to the principles of the present invention; and

FIG. 6 is a cross-section view of the packaging system viewed in the direction of arrow 3-3 shown in FIG. 2.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

Referring to FIG. 1, a packaging system or cartridge for a two-part adhesive is generally indicated by reference number 10. The packaging system 10 is configured to store two separate components or parts of a two-part adhesive compound. For example, the two-part adhesive is a polyurethane adhesive for use on roofing substrates. Prior to mixing, the adhesive is comprised of two separate parts including an isocyanate blend and a polyol blend. The packaging system 10 includes an “A” side container 10A attached to a “B” side container 10B. Each of the containers 10A and 10B define a storage space 12A and 12B, respectively. Each space 12A and 12B stores a different part of the two-part adhesive compound. The spaces 12A and 12B are separated from one another by an interior wall 14 in order to prevent mixing of the parts prior to application of the adhesive on a substrate. In one example, the containers 10A and 10B are each generally cylindrical and are formed from a single molded body, though it should be appreciated that the containers 10A and 10B may have other shapes and be made from separately formed, attached components without departing from the scope of the present invention.

The packaging system 10 includes an outlet 16 located on an end of the containers 10A and 10B. The outlet 16 includes an “A” side port 18A and a “B” side port 18B that communicate with the spaces 12A and 12B, respectively. The ports 18A and 18B are configured to allow the parts of the adhesive compound stored in the packaging system 10 to be pumped, pushed, or otherwise forced out of the containers 10A and 10B. For example, where the adhesive compound is pushed out of the packaging system 10, the packaging system 10 includes a piston 25A disposed in an open end of the container 10A and a piston 25B disposed in an end of the container 10B. The pistons 25A and 25B are in contact with the contents of the containers 10A and 10B, respectively. The pistons 25A and 25B may be separate pieces or connected. Pushing the pistons 25A and 25B forces the adhesive compound out of the packaging system 10 as described below.

The ports 18A and 18B communicate from the spaces 12A and 12B, respectively, through a connector 20. The connector 20 is a cylindrical extension located the end of the containers 10A and 10B opposite the pistons 25A and 25B. The connector 20 includes a flat or planar top surface 22 and a threaded side surface 24. It should be appreciated that the side surface 24 may include other kinds of connection features in addition to or in place of threads, such as lips or grooves, without departing from the scope of the present invention. The planar top surface 22 is preferably completely flat. A membrane 26 is disposed overtop the flat top surface 22. The membrane 26 is preferably a light gauge foil, a plastic coated foil, or laminates of paper, foil, and/or plastics. The membrane 26 is adhered to the flat top surface 22 by an adhesive disposed circumferentially around each of the ports 18A and 18B. A cap 28 is removably attached to the connector 20 via mating threads (not shown) complementary to the threaded side surface 24. Alternatively a membrane constructed of foil or coated paper or foil may simply be held in place by crimping the membrane onto the threaded sides of connector 20 by the attachment of the cap 28. Alternatively a heat-shrink plastic or UV activated shrinkable plastic may be used to secure the membrane over the connector 20. The cap 28 securely fits overtop the connector 20 and the membrane 26 to protect the membrane 26 during shipment or storage of the packaging system 10. The inside of the cap 28 is preferably a flat surface that seats firmly against the membrane 26 to prevent premature rupture of the membrane 26 during shipping and handling.

Turning to FIG. 4, prior to application of the adhesive, the cap 28 is removed from the adhesive system 10 thereby exposing the connector 20 and the membrane 26. An applicator nozzle 30 is then attached to the connector 20 via mating threads (not shown) complementary to the threaded side surface 24. The applicator nozzle 30 is an extended member that mixes the “A” side fluid with the “B” side fluid. The nozzle 30 is disposable and is preferably an element, static mixing nozzle, though it should be appreciated that other types and grades of nozzles may be employed without departing from the scope of the present invention.

The packaging system 10 and attached connector 20 are then loaded into an applicator device 32. An exemplary applicator device is disclosed in commonly owned U.S. Pat. No. 7,056,556, hereby incorporated by reference. It should be appreciated that any other number of applicator devices such as pneumatic single-bead applicators, battery powered single-bead applicators, manual applicators, among other devices may be employed without departing from the scope of the present invention. Contractors often are required to pre-attach the mixing nozzle 30 to the packaging system 10 to efficiently stage a job. Once pre-staged, job interruptions such as rainstorms can occur. Isocyanates, commonly used in 2-part polyurethane adhesives are moisture sensitive and rainwater dripping into a mixing nozzle can cause a chemical reaction to occur. Likewise, pre-staged jobs left overnight can suffer from dew forming in the mixing nozzle and causing reaction of the isocyanate. In addition, contractors often load the cartridges into equipment and then must pause while they wait for obstructions to be removed from the path of intended adhesive application. This is especially an issue for newer low-viscosity adhesive formulas for applications such as membrane attachment that can be problematic due to how fast the low-viscosity adhesives run into the nozzle 30 when loaded into the applicator 32. However, the membrane 26 prevents the adhesive parts from draining through the ports 18A and 18B when stored without the cap 28 thereby preventing the adhesive parts from mixing prematurely in the applicator 20 or nozzle 30. Some adhesives are formulated with substantially different viscosities in the polyol and isocyanate portions. In this case the lower viscosity portion tends to gravity feed into the mixing nozzle prior to the mechanical operation of the equipment causing an off-ratio adhesive mix during the initial dispense. The off-ratio adhesive may not perform as expected. The packaging system 10 may then be installed and stored in the device 32 without the applicator 20 becoming blocked due to the adhesive components crosslinking in the applicator 20 or without off-ratio initial dispenses or without messy adhesive draining through the mixing tip.

To apply the adhesive, the device 32 pumps, pushes, or otherwise forces the components out of the packaging system 10. The components create a pressure on the membrane 26 which ruptures or breaks the membrane 26, thereby allowing the components to enter the applicator 20. The membrane 26 has a pressure breaking point that allows the membrane 26 to burst before the pressure in the containers 10A and 10B builds such that the components leak out of the back sides of the containers 10A and 10B. The applicator 20 mixes the A and B side components and the combined fluid exits the applicator 20 and is dispensed in the form of elongated beads on a substrate 34. The mixed compound then cures and forms an adhesive.

Turning to FIGS. 5 and 6, and alternate embodiment of a packaging system is generally indicated by reference number 10′. The packaging system 10′ is similar to the packaging system 10 and like components are indicated by like reference numbers. However, the packaging system 10′ includes a radial flange 40 disposed along the circumference of the connector 20. The radial flange 40 surrounds the ports 18A and 18B. A linear flange 42 is disposed between the ports 18A and 18B thereby bifurcating the radial flange 40. The membrane 26 is disposed overtop the radial flange 40 and the linear flange 42. The membrane 26 is adhered to the radial flange 40 and the linear flange 42 by an adhesive disposed on the radial flange 40 and the linear flange 42. The packaging system 10′ operates in a manner similar to the packaging system 10.

The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. 

The following is claimed:
 1. A package system comprising: a first container that defines a first space; a second container that defines a second space, the second container connected to the first container; a connector connected to an outer surface of the first container and an outer surface of the second container, wherein the connector has an outer surface, a side surface, and a connection feature disposed on the side surface; a first port disposed in the outer surface of the connector and in communication with the first space; a second port disposed in the outer surface of the connector and in communication with the second space; and a membrane adhered to the outer surface of the connector, wherein the membrane covers the first port and the second port.
 2. The package system of claim 1 further comprising a cap removably attached to the connector by the connection feature, wherein the cap contacts the membrane.
 3. The package system of claim 1 further comprising a mixing nozzle removably attached to the connector by the connection feature, wherein the mixing nozzle is disposed overtop the membrane.
 4. The package system of claim 3 wherein the connection feature includes threads.
 5. The package system of claim 4 wherein the connector is fixedly connected to the first and second containers.
 6. The package system of claim 5 further comprising a polyol disposed within the first space and an isocyanate disposed within the second space, and wherein the polyol and the isocyanate are mixed by the mixing nozzle to form a urethane adhesive.
 7. The package system of claim 6 further comprising a first piston disposed in the first space and a second piston disposed in the second space, and wherein the pistons move to push the polyol and the isocyanate out through the ports to break the membrane and enter the mixing nozzle.
 8. The package system of claim 7 wherein the first piston is in contact with the polyol and the second piston is in contact with the isocyanate.
 9. The package system of claim 1 wherein the outer surface of the connector is planar.
 10. The package system of claim 1 wherein the connector includes a peripheral flange disposed along an outer circumference of the connector and a linear flange disposed on the outer surface between the first port and the second port, and wherein the membrane is adhered to the peripheral flange and the linear flange.
 11. A package system comprising: a first container that defines a first space; a second container that defines a second space, the second container connected to the first container; a connector connected to a outer surface of the first container and an outer surface of the second container, wherein the connector has a planar outer surface, a side surface, and a connection feature disposed on the side surface; a first port disposed in the planar outer surface of the connector and in communication with the first space; a second port disposed in the planar outer surface of the connector and in communication with the second space; and a membrane adhered to the outer surface of the connector, wherein the membrane covers the first port and the second port.
 12. The package system of claim 11 further comprising a cap removably attached to the connector by the connection feature, wherein the cap contacts the membrane.
 13. The package system of claim 11 further comprising a mixing nozzle removably attached to the connector by the connection feature, wherein the mixing nozzle is disposed overtop the membrane.
 14. The package system of claim 13 wherein the connection feature includes threads.
 15. The package system of claim 14 wherein the connector is fixedly connected to the first and second containers.
 16. The package system of claim 15 further comprising a polyol disposed within the first space and an isocyanate disposed within the second space, and wherein the polyol and the isocyanate are mixed by the mixing nozzle to form a urethane adhesive.
 17. The package system of claim 16 further comprising a first piston disposed in the first space and a second piston disposed in the second space, and wherein the pistons move to push the polyol and the isocyanate out through the ports to break the membrane and enter the mixing nozzle.
 18. The package system of claim 17 wherein the first piston is in contact with the polyol and the second piston is in contact with the isocyanate.
 19. A package system comprising: a first container that defines a first space; a second container that defines a second space, the second container connected to the first container; a connector connected to an outer surface of the first container and an outer surface of the second container, wherein the connector has an outer surface, a peripheral flange disposed along an outer circumference of the outer surface of the connector and a linear flange disposed radially on the outer surface of the connector; a first port disposed in the outer surface of the connector and in communication with the first space; a second port disposed in the outer surface of the connector and in communication with the second space, wherein the second port is located on an opposite side of the linear flange than the first port; and a membrane adhered to the peripheral flange and the linear flange of the connector, wherein the membrane covers the first port and the second port.
 20. The package system of claim 19 further comprising a mixing nozzle removably attached to the connector by the connection feature, wherein the mixing nozzle is disposed overtop the membrane. 